Can testing machine



Oct. 20, 1964 J.H. wEsT CAN TESTING MAcHINE 5 Sheets-Sheet 1 Filed July 7, 1961 INVENTOR. JOHN //G WEST lil/MQW ATTCRNEYS Oct. 20, 1964 J. H. wlEsT CAN TESTING MACHINE 5 Sheets-Sheet 2 Filed July 7. 1961 Olll mdms In' VM NS ATTORNEYS Oct. 20, 1964 J. H. wEsr 3,153,485

, CAN TESTING MACHINE Filed July '7. 1961 Eff.

5 Sheecs--SheefI 3 ATTORN EYS Oct. 20, 1964 J. H. wEs'r 3,153,485

CAN TESTING MACHINE Filed July 7. 1961 5 Sheets-Sheet 4 INVEN TOR.

JUHA/ HA/c; W55 7 BY@ n ATTORNEYS Oct. 20, 1964 J. H. wl-:s'r

CAN TESTING MACHINE 5 SheetsfSheet 5 Filed July 7. 1961 INVENTOR.

m www E W.M.n w@ A M M r..

United States Patent s-,rssass CAN INGMACHENE lohn. HaigWest, fniiington, Qnta'rio, Canada,V assigner 1to American Can Company, New`York,N.Y.,'a corporation of Newfliersey Filed July 7,1961, Ser. No. 122,552 5 Claims. (Cl. 26E-HSS) 'The .present inventionrelates to can testing machines .and hasL particular reference to a machinev for detecting 1 defectively .sealed or `processed cans .by probing the can ends to detect abnormal variations in the position of one `or :both of the .texiblecan end panels.

iIn ymany present .day canning `procedures'which embody vacuum'or ypressures sealing, non-atmospheric pressures areicreated withinthe sealed cans. iFrequently, too,'such -pressures result from `the liberation or absorption ofgases by `the product after thexcan has .been sealed. If these internal pressures vary suiciently from `the atmospheric pressure, they usually result in aiiexing of the can end '.zpanels. ,Thus, ifa vacutnn-isl present within the' can, its end panels are forced to assume a concave shapegif an e'Xcessive'gpositive pressure existsfthey are bulged koutwardly. `'lorrna'll-thecan end panels'a-re so designed that `even when in outwardly fleXed position they Ado not .project outwardly beyondthe vvplanes of the outer edges of the can end seam.

There are, however, numerousfsituations where the desired vacuums` or pressure conditions 4.are not `obtained withinthe cans. "For example, if Lthe pressureswithin the causare-greater thananticipated, as may be caused byfood spoilage,' :the can ends are forced outwardly beyond, the end seams, `thus producing what are termed bythe tradeas rockers AsV another example, in instances where the cans are-closed under vacuum, if the desired degree of -va'cuumisinot obtained due to leakage of the cans, its end panelswill `not eX inwardly vtov the desired degree, but willretain or -return to their initially flat contour.

The :present invention provides a machine which makes vvit'possible to detect such labnormal pressure conditions `within the cans by utilizing `pivoted probe arms which engage the Opposite end panels ofthe cans and indicate when they have an abnormal contour. When such ab- .,inormal can ends are encountered, the probe arms operate switches which energize a control circuit which operates -toeject .theabnormalcans from the machine. in order -to obviate the need-.to indexvthe cans into the machine, a Ymaster switch is utilized-which is wired in series into the controlcircuitfso thatthe circuit can be, closed only when the can is accurately located in testing position, thus preventing actuation of the/control circuit by the can end ,seams as 4the can enters the testing station.

An object ofthe present invention is the provision of a can testing mechanism which is simple and inexpensive in construction and which functions to detect and eject cans having abnormal exterior end'contours.

yAnother objectpof the invention is the provision in such a machine of a pair of can end engagingprobe arms which operate independently oi each other to detect abnor- .malities in either or both ofthe can ends.

' Still another object of the invention is the provision in such a machine of cam `means formed integral with the `probe arms to automatically center the cans between the probe arms without play and without chatter-to thereby -`make'possible a very accurate testing operation.

` `con'ipanying drawings, disclosesa kpreferred embodiment thereof.

ICC

Referring now to the drawings:

FIGURE 1 illustrates aside elevation of a .can testing machine embodying the principles of the insta-nt invention;

FIG. 2 is a horizontal sectiontalren substantially along the line.-2-2 of-FIG. 1;

FIG. 3 is a horizontal section similartoFIG. 2 but illustrating only the testing station of the imachine, the yview showing a eanbeing Vcentered by :the -inner cam edges of the pivoted-v probe arms as `its enters the testing station;

FIG. 4-is a View similar-'to FIG. 3 but-showing a centered, abnormal-ly bulged can in final'testing `position in the testing station; j

PEG. 5 -is V-ahorizontal :section similar to FIG. 2 but illustrating only the ejectingl'station of the 'machine --and -showing .the abnormallybulged can in the process -of being ejected;

`FlGURES' and 7 are verticalsectionson an enlarged --scale taken substantially along the llines-omo and '7-7 respectively of FIG. -2;

1F IG 8 y.is a wiringdiagramfofthe machine of FIGURES v.1-8 ,with the detector switches wired in parallel to each `other to detect cans having abnormalities inieither or kboth end-panels;

VKFIG. .-9 is a view `similar toF-IG. .Snbut `illustrating a modied `control circuit wherein the detector switches are wired in series with each other;

FIGURES 10 .and 11 vare schematic `views of the operation of the detector switches of -the `.machine when arranged to detect .andeject cans having. abnormally bulged ends audio .pass canshaving `normally bulged ends, FIG.

.stant invention, the drawings Ydisclose a can testing -ma chine,.the principal lparts of iwhichare mounted ona mam frame. .'Thesealed cans C which ,are 1beingdested are eacnformed with.the usual cylindrical .body B which has a ,can end E secured at each end in a double seam D. Each can end E is formed with a central panelPwhich is adaptedtoex inwardly or outwardly, depending on the` pressure within the sealedcan' C. The vmachine illustrated in FIGS. 1-8 is arranged to detect rockers, which are cans whose end panels are tiered convexly outwardly Vto a greater degree than are the end panels in normalcans. The cans C are fed into the machine kalong an inclined Y, gravity runway `2315. As they approach the machine, the

vmounted for rotation on a shaft. 26 which iscarried at ,the end `of a yoke arm 2.8 which is pivotally V'mounted on a pivot.pin Ak3i) carried by the upper portion of the machine frame' 20.

A s eachcan C engages the roller,24,.it is slowed down, thus giving the preceding can C which has just been releasedV bythe roller 24 a chance to roll ahead of the engaged can to create suiiicient Vspace 'between the successive cans to permitrthe 4machine to operate successfully. The speed of free rotation of lthe roller 24 can be controlled -by va `spring-backed friction washer 32 wlnchis mounted ori-the shaft 26 and'engages against one side of the roller 24.

As 'each canC ist-released -bythe spacing device, it

rolls down the gravity chute 22 and into the runway, generally designated by the numeral 33, of the can testing machine. The runway 33 is composed of a pair of spaced horizontal plates 34, 36 which extend the length of the machine and engage and support the opposite end seams D of the rolling cans C.

Each can C, as it enters the machine, passes between a pair of side guides 38, 40 which are spaced from each other a distance somewhat in excess of the normal height of the cans being tested so that cans will roll freely and easily. The glide 38 comprises an angle iron which is secured to the plate 34 and extends the full length of the machine while the guide 40 comprises the inner edge of a llat plate 42 which is mounted above the plate 36 and extends only through the testing station, designated by the letter T, which comprises the first portion of the machine. A second plate 44, somewhat smaller than the plate 42 is mounted above the support plate 34 but Y spaced inwardly of the guide 38. The purpose of this plate 44 will be explained later.

As a can C enters the testing station T, it is engaged by a flexible drive belt 50 (see FIG. 1) which operates around a pair of pulleys 52, S4 which are keyed to shafts 56, 58 which are mounted for vertical adjustment in slots 60 which are formed in vertical brackets 62 which form part of the machine frame 20. The beltl 50 is driven in a counter-clockwise direction, as viewed in FIG. 1, by a drive motor 64 via a belt 66 which operates around a large pulley 68 which is keyed to the shaft 58 as seen in FIG. 1.

The lower flight of the belt 50 is pressed into driving engagement against the upper portions of the body of the can C by a pair of small grooved pressure rollers 70 which are pressed downwardly by spring arms 72 which extend from a small bracket 74 carried by the upper portion of the machine frame 20.

As each can C is rolled along the runway 33 by the belt 50, its end seams D come into contact with the inner edges 80 of a pair of probe arms 81, 82 which are are initially contacted by the can C are formed in the" shape of gently curving cams which function to center the rolling can C in the runway 33, the fact that the can C is moving forward in rolling engagement with the belt permitting it to move laterally with respect to the belt nate in rounded feeler lobes 92 which are disposed adjacent the free extremities of the arms 81, 82.

The forward movement of the can C along the cam surfaces 80 causes the probe arms 81, 82 to pivot open as the feeler lobes 92 ride `over the can end seams D and onto the can end panels P. This pivotal, spreading movement of the probe arms 81, 82 brings a pair of lugs 94, one of which is carried by each of the probe arms, into contact with the actuators 96 of a pair of normally open snap switches 98, 100, one of which is mounted on each of the plates 42, 44 outwardly of the arms 81, 82. Y

The switches 98, 100 are so positioned relative to the I probe arms 81, 82 that their plungers 102 are depressed a suicient distance to close the switch contacts when l the feeler lobes 92 of the probe arms 81, 82 pass. over the can end seams D. Thus, the switches 98, 100 will be closed by each can C las it enters the testing station T, regardless of whether it is a good can or a bad can.

As seen in FIG. 8, the snap switches 98, 100 are connected inparallel with each other in a detector circuit 50. The cam edges 80 of the probe arms 81, 82 termi- G which also includes a normally closed time delay relay 104. In order to prevent the detector circuit G from being energized Ias the end seams D of each can C close the switches 98, 100, a third, normally open snap switch 106 is incorporated in the detector circuit G 4in series with each of the switches 98, 100 and with the relay 104.

The switch 106, which may be termed a master switch, is mounted below the runway 33 with its plunger 108 (see FIGS. 2 and 6) in transverse alignment with the high spots of the feeler lobes 92 so that it is closed only when each can C is fully within .the testing station T with the feeler lobes 92 in contact with the `axially central portions of its end panels P. The switch 106 is not closed when the feeler lobes 92 are in contact with the can end seams D. l

Thus, when a normal can, i.e., a can such as is shown in FIG. 10 wherein the end panels P are not bulged outwardly as far as the planes of the outer extremities of the can end seams D, the feeler lobes 92 will move inwardly after they ride off the can end seams D and onto the can end panels P, thus causing the snap switches 98, 100 to return to their normally open position, with the result that no current flows in the detector circuit G, even though at this time the master switch 106 yis closed by the can C.

If, however, the can end panels P are abnormally bulged, as shown in FIG. 11, so that they are level with or beyond the planes of the outer extremities of the can end seams D, the switches 98, 100 will be held in closed position by the probe arms 81, 82 when the can C is fully in the testing station T. Since the master switch 106 is also closed at such time, current flows in lthe detector circuit G, thus energizing the normally closed relay 104 land opening its contacts t-o thereby break the flow of current in an ejector circuit H, thus de-energizing a pair of solenoids 110, 112 which are mounted in parallel with each other in the circuit H (see FIG. 8).

The solenoids 110, 112 are disposed 0n either side of the runway 33 at the rear portion of the machine which portion may be designated as an ejector station J. As best seen in FIGURES 2 and 6, the support plates 34, 36 are cut away at the ejector station I and the gaps created thereby are bridged by pivotally mounted track sections 114, 116, the free ends of which are connected to the armatures 118 of the solenoids 110, 112 and are normally held in closed, can supporting position, against the pressures of a pair of compression springs 120, by the normally energized solenoids 110, 112. However, when an abnormal can is detected, the llow of current in the ejector circuit H is cut off, thus de-energizing the solenoids 110, 112 and permitting the springs 120 to pivotally move the track sections 114, 116 outwardly into open position wherein they are not capable of engaging beneath and supporting a can C.

The time delay relay 104 is set so that the track sections 114, 116 remain in this open position until the abnormal can is rolled from the testing station T to the ejecting station I by the belt 50 and drops through the runway 33 between the open track sections 114, 116 (see FIG. 5) to any suitable place of deposit, such as a rej ceptacle 122. Thereafter, the time delay relay 104 closes,

j ly open position, and the detector circuit G remains open.

Consequently, the solenoids 110, 112 remain energized, the track sections 114, 116 remain in can-supporting position, and the normal can rolls through the ejector station J unmolested and is discharged into a discharge chute 124.

FIGURES 12 and 13 illustrate the operation of the machine when utilized in conjunction with cans C which have been vacuumized before sealing. The can end panels P in such cans are normally bowed inwardly due to the pressure differential, as seer in FIG. 12.' However, the

end panels P of leaky cans are not so bowed, but remainV substantially i'lat, as seen in FG. 13, because they retain little or no internal vacuum. The operation of the machine with vacuumized cans is very similar to its operation with bulged cans, the switches 9S, 100 being normally open but being closed by thedouble seams D of each can C as it enters the testing station T. The master switch 106 however', remains 'open until the can C is fully within the station T, so that the detector circuit G is not closed by virtue of the action of the can end seams D in closing the switches 9S, 100.

After the feeler lobes 92 ride olf the can end seams D, they ride onto the can end panels P, thus permitting the feeler probes 81, 82 to move inwardly. The switches 98, Mtl are set so that they remain closed in the event the can end panels P are flat, as seen in FiG. 13. Since at this time the master switch 106 is closed by the can C, the detector circuit G is energized, the track sections 114, 116 are moved to open position and the leaky can is ejected from the machine when it reaches the ejector station J.

lf the can C is a normal, non-leaky can, the feeler lobes 81, S2. move farther inwardly because of the bowed can end panels P, and such movement permits the switches 98, 10@ to return to their normal open position so that the detector circuit G is not energized and the can C is not ejected.

In the two testing operations just described, both ends of the cans being tested were of uniform construction and contour so that they iiexed outwardly or inwardly to the same degree, but in opposite directions. It is possible, however, to operate the machine of the instant invention in conjunction with cans wherein the end members are of non-uniform construction, so that the opposite ends of the cans do not flex to a uniform degree.

FIGURE 14 shows a can which is so constructed that one of its ends, the end to the right as viewed in FIG. 14, is made of thinner material and is thus more tiexible than its other end, which may also be provided with reinforcing corrugations (not shown) to limit or preventing its flexing. When a can of such construction having its flexible end bulged outwardly to an abnormal degree is sent through the machine, the probe arm 81 will contact the outwardly bulged end panel P and will thus close the switch 98 while the probe arm S2 which contacts the reinforced non-bulged end will permit the switch associated with it to return to its normally open position. Since, however, the switches 98, 100 are connected in parallel in the detector circuit G of FIG. 8, it is only necessary that one of them be closed in order to energize the control circuit G. Thus, the can of FIG. 14 will be ejected when it reaches the ejecting station I. This will be true regardless of which end of the can is abnormally contoured. There is no appreciable lateral movement of the can during this testing operation, even though the springs 88 are compressed to diiferent degrees.

It is obvious that the detector switches 98, 100 and the `detector and ejector circuits G and H may be suitably altered to enable the machine of the instant invention to detect many ditierent kinds of can abnormalities. FIG. 9 shows a control circuit which may be utilized in place of the control circuit of FIG. 8. The circuit of FIG. 9 v

description, and it will be apparent that various changes` J9 may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacricing all of its material advantages, the form hereinbefore described being 'merely a preferred embodiment thereof.

I claim: y

1. A machine for detecting and ejecting sealed cans having abnormally contoured end panels, comprising:

a can runway in which the cans are advanced with their axes normal to the direction of advancement,

a pair of probe arms pivotally mounted adjacent one of the ends thereof on opposite sides of said runway and disposed in transverse alignment,

means for resiliently urging each of said probe arms inwardly to a position wherein the free end portion thereof extends into said runway in the path of the cans,

each of said probe arms being of substantially rigid construction and having on its inner surface a gradually inwardly extending cam portion for engaging the adjacent end seams of the cans to center them in the runway.

said cam portion merging into a feeler portion formed on the inner surface of each of said probe arms adjacent the free end portion thereof and adapted to ride over the adjacent end seams of the cans and to engage the adjacent end panels of the cans after they are centered in said runway by said cam portions,

a detector switch disposed adjacent each of said probe arms and operable thereby when said probe arms engage abnormally contoured end panels,

a master switch connected to said detector switches and having an actuating member mounted in said runway in transverse alignment with said feeler portions of said probe arms, said actuating member being engageable by the cans in'said runway to actuate said master switch only when said feeler portions of said probe arms are in engagement with the central portions of the can end panels,

ejector means for ejecting cans having abnormally contoured end panels, and

a control circuit for operating said ejector means, said control circuit including said detector switches and said master switch, said master switch being connected into said control circuit in series with said detector switches so that said detector switches alone are not operable to cause ejection of cans having abnormally contoured end panels.

2. The machine of claim l wherein said ejector means include a gate section formed in said runway to separate the normally contoured cans from the abnormally contoured cans.

3. The machine of claim 2 wherein said control circuit includes time delay means for insuring operation of said ejector gate section a sufficient period of time for complete ejection of each abnormally contoured can from said runway.

4. The machine of claim 1 wherein one of said detector switches is connected in parallel with the other of said detector switches in said control circuit.

5. The machine of claim 1 wherein one of said detector switches is connected in series with the other of said detector switches in said control circuit.

References Cited in the tile of this patent UNITED STATES PATENTS 2,293,586 Bardet Aug. 18, 1942 2,327,629 Fedorchak Aug. 24, 1943 2,355,051 Braucher Aug. 8, 1944 2,400,507 Henszey May 21, 1946 2,689,647 Hoffstetter Sept. 21, 1954 3,003,631 Stock Oct. 10, 1961 

1. A MACHINE FOR DETECTING AND EJECTING SEALED CANS HAVING ABNORMALLY CONTOURED END PANELS, COMPRISING; A CAN RUNWAY IN WHICH THE CANS ARE ADVANCED WITH THEIR AXES NORMAL TO THE DIRECTION OF ADVANCEMENT A PAIR OF PROBE ARMS PIVOTALLY MOUNTED ADJACENT ONE OF THE ENDS THEREOF ON OPPOSITE SIDES OF SAID RUNWAY AND DISPOSED IN TRANSVERSE ALIGNMENT, MEANS FOR RESILIENTLY URGING EACH OF SAID PROBE ARMS INWARDLY TO A POSITION WHEREIN THE FREE END PORTION THEREOF EXTENDS INTO SAID RUNWAY IN THE PATH OF THE CANS, EACH OF SAID PROBE ARMS BEING OF SUBSTANTIALLY RIGID CONSTRUCTION AND HAVING ON ITS INNER SURFACE A GRADUALLY INWARDLY EXTENDING CAM PORTION FOR ENGAGING THE ADJACENT END SEAMS OF THE CANS TO CENTER THEM IN THE RUNWAY. SAID CAM PORTION MERGING INTO A FEELER PORTION FORMED ON THE INNER SURFACE OF EACH OF SAID PROBE ARMS ADJACENT THE FREE END PORTION THEREOF AND ADAPTED TO RIDE OVER THE ADJACENT END SEAMS OF THE CANS AND TO ENGAGE THE ADJACENT END PANELS OF THE CANS AFTER THEY ARE CENTERED IN SAID RUNWAY BY SAID CAM PORTIONS, A DETECTOR SWITCH DISPOSED ADJACENT EACH OF SAID PROBE ARMS AND OPERABLE THEREBY WHEN SAID PROBE ARMS ENGAGE ABNORMALLY CONTOURED END PANELS, A MASTER SWITCH CONNECTED TO SAID DETECTOR SWITCHES AND HAVING AN ACTUATING MEMBER MOUNTED IN SAID RUNWAY IN TRANSVERSE ALIGNMENT WITH SAID FEELER PORTIONS OF SAID PROBE ARMS, SAID ACTUATING MEMBER BEING ENGAGEABLE BY THE CANS IN SAID RUNWAY TO ACTUATE SAID MASTER SWITCH ONLY WHEN SAID FEELER PORTIONS OF SAID PROBE ARMS ARE IN ENGAGEMENT WITH THE CENTRAL PORTION OF THE CAN END PANELS, EJECTOR MEANS FOR EJECTING CANS HAVING ABNORMALLY CONTOURED END PANELS, AND A CONTROL CIRCUIT FOR OPERATING SAID EJECTOR MEANS, SAID CONTROL CIRCUIT INCLUDING SAID DETECTOR SWITCHES AND SAID MASTER SWITCH, SAID MASTER SWITCH BEING CONNECTED INTO SAID CONTROL CIRCUIT IN SERIES WITH SAID DETECTOR SWITCHES SO THAT SAID DETECTOR SWITCHES ALONE ARE NOT OPERABLE TO CAUSE EJECTION OF CANS HAVING ABNORMALLY CONTOURED END PANELS. 